The invention relates to a process for selecting and/or obtaining nucleic acid probes capable of detecting new variable number tandem repeat regions present in the genomes of higher eucaryotes, probes obtainable in this way, and their applications.
With the development of molecular biology and its application to daily life, circumstances requiring genetic identification are increasingly frequent. Among these we may cite identification of an individual, particularly in police investigations or paternity testing, identification of a cell line, or checking the origin of a human, animal, or plant seed.
However, in view of the complexity of the genomes in higher eucaryotes, a complete genome analysis for a given individual cannot be contemplated at the present time.
Hence it is necessary to resort to using markers of this genetic identity.
It has recently been shown that useful markers designated "variable number tandem repeat regions" (VNTR regions or VNTRs for short) exist in the genomes of higher eucaryotes; these regions are also known as "hypervariable regions" or "minisatellite regions."
Each locus corresponding to a VNTR is composed of a series of tandem repeat nucleotides of which the number of repeats varies from one individual to another. However, not all the repeated sequences are fully identical. Nonetheless, for a given species, a given locus repeats largely identically.
The various VNTRs of a given individual are dispersed throughout the genome and are distinguished from each other, not only by the sequence of the repeated motif, but also by the number of repetitions of their own motif.
Of the methods for detecting these regions used to date, one may cite the screening of a bank using nucleotide probes with natural tandem repeats (Wong et al., Ann. Hum. Genet., 51, 269-288, 1987) or synthetic probes (Zischler et al., Genomics, 13, 983-990, 1992). One may also cite the method described in French patent application FR 91.10516, consisting of screening a bank enriched with VNTRs using nucleotide probes with artificial tandem repeats, as well as the method consisting of a systematic search in a genomic bank (Armour et al., Genomics, 8, 501-512).
However, these methods have proved inadequate in that, thus far, they have enabled documentation of only about 10% of the estimated number of VNTRs for the human species.